Search results for: sociocultural dynamics

Authors: Kadda Boumediene, Mohamed Bouzit

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The prediction of the flow around marine propellers and vessel hulls propeller interaction is one of the challenges of Computational fluid dynamics (CFD). The CFD has emerged as a potential tool in recent years and has promising applications. The objective of the current study is to predict the hydrodynamic performances of HSP marine propeller in open water and behind a vessel. The unsteady 3-D flow was modeled numerically along with respectively the K-ω standard and K-ω SST turbulence models for steady and unsteady cases. The hydrodynamic performances such us a torque and thrust coefficients and efficiency show good agreement with the experiment results.

Keywords: seiun maru propeller, steady, unstead, CFD, HSP

Procedia PDF Downloads 305

Authors: Himani Sharma, Amit Agrawal

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Stability of the Cassie and Wenzel wetting states depends on intrinsic contact angle and geometric features on a surface that was exploited in capturing biofluids in microwells. However, the mechanism of imbibition of biofluids in the microwells is not well implied in terms of wettability of a substrate. In this work, we experimentally demonstrated filling dynamics in hydrophilic and hydrophobic microwells by protein solutions. Towards this, we utilized lotus leaf as a mold to fabricate microwells on a Polydimethylsiloxane (PDMS) surface. Lotus leaf containing micrometer-sized blunt-conical shaped pillars with a height of 8-15 µm and diameter of 3-8 µm were transferred on to PDMS. Furthermore, PDMS surface was treated with oxygen plasma to render the hydrophilic nature. A 10µL droplets containing fluorescein isothiocyanate (FITC) - labelled bovine serum albumin (BSA) were rested on both hydrophobic (θa = 108o, where θa is the apparent contact angle) and hydrophilic (θa = 60o) PDMS surfaces. A time-dependent fluorescence microscopy was conducted on these modified PDMS surfaces by recording the fluorescent intensity over a 5 minute period. It was observed that, initially (at t=1 min) FITC-BSA was accumulated on the periphery of both hydrophilic and hydrophobic microwells due to incomplete penetration of liquid-gas meniscus. This deposition of FITC-BSA on periphery of microwell was not changed with time for hydrophobic surfaces, whereas, a complete filling was occurred in hydrophilic microwells (at t=5 mins). This attributes to a gradual movement of three-phase contact line along the vertical surface of the hydrophilic microwells as compared to stable pinning in the hydrophobic microwells as confirmed by Surface Evolver simulations. In addition, if the cavities are presented on hydrophobic surfaces, air bubbles will be trapped inside the cavities once the aqueous solution is placed over these surfaces, resulting in the Cassie-Baxter wetting state. This condition hinders trapping of proteins inside the microwells. Thus, it is necessary to impart hydrophilicity to the microwell surfaces so as to induce the Wenzel state, such that, an entire solution will be fully in contact with the walls of microwells. Imbibition of microwells by protein solutions was analyzed in terms fluorescent intensity versus time. The present work underlines the importance of geometry of microwells and surface wettability of substrate in wetting and effective capturing of solid sub-phases in biofluids.

Keywords: BSA, microwells, surface evolver, wettability

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Authors: Davendra Singh Malik

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India is one of the mega-biodiversity countries in the world and contributing about 11.72% of global fish diversity. The Yamuna river is the longest tributary of Ganga river ecosystem, providing a natural habitat for existing fish diversity of Himalayan region of Indian subcontinent. The several hydropower dams and barrages have been constructed on different locations of major rivers in Garhwal region. These dams have caused a major ecological threat to change existing fresh water ecosystems altering water flows, interrupting ecological connectivity, fragmenting habitats and native riverine fish species. Mahseer fishes (Indian carp) of the genus Tor, are large cyprinids endemic to continental Asia popularly known as ‘Game or sport fishes’ have continued to be decimated by fragmented natural habitats due to damming the water flow in riverine system and categorized as threatened fishes of India. The fresh water fish diversity as 24 fish species were recorded from Yamuna river. The present fish catch data has revealed that mahseer fishes (Tor tor and Tor putitora) were contributed about 32.5 %, 25.6 % and 18.2 % in upper, middle and lower riverine stretches of Yaumna river. The length range of mahseer (360-450mm) recorded as dominant size of catch composition. The CPUE (catch per unit effort) of mahseer fishes also indicated about a sharp decline of fish biomass, changing growth pattern, sex ratio and maturity stages of fishes. Only 12.5 – 14.8 % mahseer female brooders have showed only maturity phases in breeding months. The fecundity of mature mahseer female fish brooders ranged from 2500-4500 no. of ova during breeding months. The present status of mahseer fishery has attributed to the over exploitative nature in Yamuna river. The mahseer population is shrinking continuously in down streams of Yamuna river due to cumulative effects of various ecological stress. Mahseer conservation programme have implemented as 'in situ fish conservation' for enhancement of viable population size of mahseer species and restore the genetic loss of mahseer fish germplasm in Yamuna river of Garhwal Himalayan region.

Keywords: conservation practice, population dynamics, tor fish species, Yamuna River

Procedia PDF Downloads 255

Authors: Rajashree Bothale, Venkateswara Rao

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Indian Himalayas also known as third pole with 0.9 Million SQ km area, contain the largest reserve of ice and snow outside poles and affect global climate and water availability in the perennial rivers. The variations in the extent of snow are indicative of climate change. The snow melt is sensitive to climate change (warming) and also an influencing factor to the climate change. A study of the spatio-temporal dynamics of snow cover and melt/freeze conditions is carried out using space based observations in visible and microwave bands. An analysis period of 2003 to 2015 is selected to identify and map the changes and trend in snow cover using Indian Remote Sensing (IRS) Advanced Wide Field Sensor (AWiFS) and Moderate Resolution Imaging Spectroradiometer(MODIS) data. For mapping of wet snow, microwave data is used, which is sensitive to the presence of liquid water in the snow. The present study uses Ku-band scatterometer data from QuikSCAT and Oceansat satellites. The enhanced resolution images at 2.25 km from the 13.6GHz sensor are used to analyze the backscatter response to dry and wet snow for the period of 2000-2013 using threshold method. The study area is divided into three major river basins namely Brahmaputra, Ganges and Indus which also represent the diversification in Himalayas as the Eastern Himalayas, Central Himalayas and Western Himalayas. Topographic variations across different zones show that a majority of the study area lies in 4000–5500 m elevation range and the maximum percent of high elevated areas (>5500 m) lies in Western Himalayas. The effect of climate change could be seen in the extent of snow cover and also on the melt/freeze status in different parts of Himalayas. Melt onset day increases from east (March11+11) to west (May12+15) with large variation in number of melt days. Western Himalayas has shorter melt duration (120+15) in comparison to Eastern Himalayas (150+16) providing lesser time for melt. Eastern Himalaya glaciers are prone for enhanced melt due to large melt duration. The extent of snow cover coupled with the status of melt/freeze indicating solar radiation can be used as precursor for monsoon prediction.

Keywords: Indian Himalaya, Scatterometer, Snow Melt/Freeze, AWiFS, Cryosphere

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Authors: Rosaline Govender, Shubnam Rambharos

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Universities are, to a certain extent, the source of under-preparedness ideologically, structurally, and pedagogically, particularly since organizational cultures often alienate students by failing to enable epistemological access. This is evident in the unsustainably low graduation rates that characterize South African higher education, which indicate that under 30% graduate in minimum time, under two-thirds graduate within 6 years, and one-third have not graduated after 10 years. Although the statistics for the Faculty of Accounting and Informatics at the Durban University of Technology (DUT) in South Africa have improved significantly from 2019 to 2021, the graduation (32%), throughput (50%), and dropout rates (16%) are still a matter for concern as the graduation rates, in particular, are quite similar to the national statistics. For our students to succeed, higher education should take a multi-pronged approach to ensure student success, and student engagement is one of the ways to support our students. Student engagement depends not only on students’ teaching and learning experiences but, more importantly, on their social and academic integration, their sense of belonging, and their emotional connections in the institution. Such experiences need to challenge students academically and engage their intellect, grow their communication skills, build self-discipline, and promote confidence. The aim of this mixed methods study is to explore the multi-pronged nature of student success within the Faculty of Accounting and Informatics at DUT and focuses on the enabling and constraining factors of student success. The sources of data were the Mid-year student experience survey (N=60), the Hambisa Student Survey (N=85), and semi structured focus group interviews with first, second, and third year students of the Faculty of Accounting and Informatics Hambisa program. The Hambisa (“Moving forward”) focus area is part of the Siyaphumelela 2.0 project at DUT and seeks to understand the multiple challenges that are impacting student success which create a large “middle” cohort of students that are stuck in transition within academic programs. Using the lens of the sociocultural influences on student engagement framework, we conducted a thematic analysis of the two surveys and focus group interviews. Preliminary findings indicate that living conditions, choice of program, access to resources, motivation, institutional support, infrastructure, and pedagogical practices impact student engagement and, thus, student success. It is envisaged that the findings from this project will assist the university in being better prepared to enable student success.

Keywords: social and academic integration, socio-cultural influences, student engagement, student success

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Authors: Feng-Hisang Lai

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CFD(Computational Fluid Dynamics) is conducted to numerically study the flow and heat transfer features of a two-pole, 6,080HP, 60Hz, 3,150V open drip-proof (ODP) motor. The stator and rotor cores in this high voltage induction motor are segmented with the use of spacers for cooling purposes, which leads to difficulties in meshing when the entire system is to be simulated. The system is divided into 4 parts, meshed separately and then combined using interfaces. The deviation between the CFD and experimental results in temperature and flow rate is less than 10%. The internal flow is further examined and a final design is proposed to reduce the winding temperature by 10 degrees.

Keywords: CFD, open drip proof, induction motor, cooling

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Authors: Moustafa Osman Mohammed

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Integration sustainability outcomes give attention to construction ecology in the design review of urban environments to comply with Earth’s System that is composed of integral parts of the (i.e., physical, chemical and biological components). Naturally, exchange patterns of industrial ecology have consistent and periodic cycles to preserve energy flows and materials in Earth’s System. When engineering topology is affecting internal and external processes in system networks, it postulated the valence of the first-level spatial outcome (i.e., project compatibility success). These instrumentalities are dependent on relating the second-level outcome (i.e., participant security satisfaction). Construction ecology approach feedback energy from resources flows between biotic and abiotic in the entire Earth’s ecosystems. These spatial outcomes are providing an innovation, as entails a wide range of interactions to state, regulate and feedback “topology” to flow as “interdisciplinary equilibrium” of ecosystems. The interrelation dynamics of ecosystems are performing a process in a certain location within an appropriate time for characterizing their unique structure in “equilibrium patterns”, such as biosphere and collecting a composite structure of many distributed feedback flows. These interdisciplinary systems regulate their dynamics within complex structures. These dynamic mechanisms of the ecosystem regulate physical and chemical properties to enable a gradual and prolonged incremental pattern to develop a stable structure. The engineering topology of construction ecology for integration sustainability outcomes offers an interesting tool for ecologists and engineers in the simulation paradigm as an initial form of development structure within compatible computer software. This approach argues from ecology, resource savings, static load design, financial other pragmatic reasons, while an artistic/architectural perspective, these are not decisive. The paper described an attempt to unify analytic and analogical spatial modeling in developing urban environments as a relational setting, using optimization software and applied as an example of integrated industrial ecology where the construction process is based on a topology optimization approach.

Keywords: construction ecology, industrial ecology, urban topology, environmental planning

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Authors: John Acire, Wilfred Lajul, Ogwang Tom

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Using a qualitative research technique, this study investigates the influence of Early Childhood Education (ECE) on learning outcomes in lower primary schools in Gulu City, Uganda. The study, which is based on Vygotsky's sociocultural theory of human learning, fills gaps in the current literature on the influence of ECE on learning outcomes. The aims of the study include analyzing the state of learning outcomes, investigating ECE practices, and determining the influence of these practices on learning outcomes in lower primary schools. The findings highlight the critical significance of ECE in promoting children's overall development. Nursery education helps children improve their handwriting, reading abilities, and general cognitive development. Children who have received nursery education have improved their abilities to handle pencils, form letters, and engage in social interactions, highlighting the significance of fine motor skills and socializing. Despite the good elements, difficulties in implementing ECE practices were found, such as differences in teaching styles, financial limits, and potential weariness due to prolonged school hours. The study suggests focused interventions to improve the effectiveness of ECE practices, ensure their connection with educational goals and maximize their influence on children's development. The study's findings show that respondents agree on the importance of nursery education in supporting holistic development, socialization, language competency, and conceptual comprehension. Challenges in nursery education, such as differences in teaching techniques and insufficient resources, highlight the need for comprehensive measures to address these challenges. Furthermore, parental engagement in home learning activities was revealed as an important factor affecting early education outcomes. Children who were engaged at home performed better in lower primary, emphasizing the value of a supportive family environment. Finally, the report suggests measures to enhance parental participation, changes in teaching methods through retraining, and age-appropriate enrolment. Future studies might concentrate on the involvement of parents, ECE policy practice, and the influence of ECE teachers on lower primary school learning results. These ideas are intended to help create a more favorable learning environment by encouraging holistic development and preparing children for success in succeeding academic levels.

Keywords: early childhood education, learning outcomes in lower primary schools, early childhood education practices, how ECE practices influence learning outcomes in lower primary schools

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Authors: Shorena Tsiklauri, Avtandil Sulaberidze, Nino Gomelauri

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In the years followed independence, an economic crisis and some conflicts led to the displacement of many people inside Georgia. The growing poverty, unemployment, low income and its unequal distribution limited access to basic social service have had a clear direct impact on Georgian population dynamics and its age-sex structure. Factors influencing the changing population age structure and urbanization include mortality, fertility, migration and expansion of urban. In this paper presents the main factors of changing the distribution by urban and rural areas. How different are the urban and rural age and sex structures? Does Georgia have the same age-sex structure among their urban and rural populations since 1950s?

Keywords: age and sex structure of population, georgia, migration, urban-rural population

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Authors: Veruska C. Dutra, Lucio F.M. Adorno, Mary L. G. S. Senna

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Since it recognized the importance of planning sustainable tourism, which has been discussed effective methods of monitoring tourist. In this sense, the indicators, can transmit a set of information about complex processes, events or trends, showing up as an important monitoring tool and aid in the environmental assessment, helping to identify the progress of it and to chart future actions, contributing, so for decision making. The World Tourism Organization - WTO recognizes the importance of indicators to appraise the tourism activity in the point of view of sustainability, launching in 1995 eleven Keys Indicators of Sustainable Tourism to assist in the monitoring of tourist destinations. So we propose a case study to examine the applicability or otherwise of a monitoring methodology and aid in the understanding of tourism sustainability, analyzing the effectiveness of local indicators on the approach defined by the WTO. The study was applied to the Lagoa da Confusão City, in the state of Tocantins - North Brazil. The case study was carried out in 2006/2007, with the guiding deductive method. The indicators were measured by specific methodologies adapted to the study site, so that could generate quantitative results which could be analyzed at the proposed scale WTO (0 to 10 points). Applied indicators: Attractive Protection – AP (level of a natural and cultural attractive protection), Sociocultural Impact–SI (level of socio-cultural impacts), Waste Management - WM (level of management of solid waste generated), Planning Process-PP (trip planning level) Tourist Satisfaction-TS (satisfaction of the tourist experience), Community Satisfaction-CS (satisfaction of the local community with the development of local tourism) and Tourism Contribution to the Local Economy-TCLE (tourist level of contribution to the local economy). The city of Lagoa da Confusão was presented as an important object of study for the methodology in question, as offered condition to analyze the indicators and the complexities that arose during the research. The data collected can help discussions on the sustainability of tourism in the destination. The indicators TS, CS, WM , PP and AP appeared as satisfactory as allowed the measurement "translating" the reality under study, unlike TCLE and the SI indicators that were not seen as reliable and clear and should be reviewed and discussed for an adaptation and replication of the same. The application and study of various indicators of sustainable tourism, give better able to analyze the local tourism situation than monitor only one of the indicators, it does not demonstrate all collected data, which could result in a superficial analysis of the tourist destination.

Keywords: indicators, Lagoa da Confusão, Tocantins, Brazil, monitoring, sustainability

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Authors: Gizem Kodak, Alper Unal, Birsen Koldemir, Tayfun Acarer

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Turkish Straits System which consists of Istanbul Strait (Bosphorus), Canakkale Strait (Dardanelles) and the Marmara Sea has a strategical location on international maritime as it is a unique waterway between the Mediterranean Sea, Black Sea and the Aegean Sea. Thus, this area has great importance since it is the only waterway between Black Sea countries and the rest of the World. Turkish Straits System has dangerous environmental factors hosts more vessel every day through developing World trade and this situation results in expanding accident risks day by day. Today, a lot of precautions have been taken to ensure safe navigation and to prevent maritime accidents, and international standards are followed to avoid maritime accidents. Despite this, the environmental factors that affect this area, trigger the maritime accidents and threaten the vessels with new accidents risks in different months with different hazards. This descriptive study consists of temporal and spatial analyses of environmental factors causing maritime accidents. This study also aims at contributing to safety navigation including monthly and regionally characteristics of variables. In this context, two different data sets are created consisting of environmental factors and accidents. This descriptive study on the accidents between 2001 and 2017 the mentioned region also studies the months and places of the accidents with environmental factor variables. Environmental factor variables are categorized as dynamic and static factors. Dynamic factors are appointed as meteorological and oceanographical while static factors are appointed as geological factors that threaten safety navigation with geometrical restricts. The variables that form dynamic factors are approached meteorological as wind direction, wind speed, wave altitude and visibility. The circulations and properties of the water mass on the system are studied as oceanographical properties. At the end of the study, the efficient meteorological and oceanographical parameters on the region are presented monthly and regionally. By this way, we acquired the monthly, seasonal and regional distributions of the accidents. Upon the analyses that are done; The Turkish Straits System that connects the Black Sea countries with the other countries and which is one of the most important parts of the world trade; is analyzed on temporal and spatial dimensions on the reasons of the accidents and have been presented as environmental factor dynamics causing maritime accidents.

Keywords: descriptive study, environmental factors, maritime accidents, statistics

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Authors: Saurabh Agarwal

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This paper attempts to formalise the effect of demographic variables like marital status, gender, occupation and age on the source of investment advice which, in turn, affect the herd behaviour of investors and probability of investment in near future. Further, postulations have been made for most preferred investment option and purpose of saving and source of investment. Impact of theoretical analysis on choice among investment alternatives has also been investigated. The analysis contributes to understanding the different investment choices made by households in India. The insights offered in the paper indirectly contribute in uncovering the various unexplained asset pricing puzzles.

Keywords: portfolio choice, investment decisions, investor’s behaviour, Indian securities market

Procedia PDF Downloads 367

Authors: Hashem M. Alargha, Mohammad O. Hamdan, Waseem H. Aziz

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Aerobatic and military pilots are subjected to high gravitational forces that could cause blackout, physical injuries or death. A CFD simulation using fluid-solid interactions scheme has been conducted to investigate the gravitational effects and hazards inside cerebral aneurysms. Medical data have been used to derive the size and geometry of a simple aneurysm on a T-shaped bifurcation. The results show that gravitational force has no effect on maximum Wall Shear Stress (WSS); hence, it will not cause aneurysm initiation/formation. However, gravitational force cause causes hypertension which could contribute to aneurysm rupture.

Keywords: aneurysm, cfd, wall shear stress, gravity, fluid dynamics, bifurcation artery

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Authors: Yun Chen, David Penton, Fazlul Karim, Santosh Aryal, Shahriar Wahid, Peter Taylor, Susan M. Cuddy

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Droughts have severely affected Afghanistan over the last four decades, leading to critical food shortages where two-thirds of the country’s population are in a food crisis. Long years of conflict have lowered the country’s ability to deal with hazards such as drought, which can rapidly escalate into disasters. Understanding the spatial and temporal distribution of droughts is needed to be able to respond effectively to disasters and plan for future occurrences. This study used Standardized Precipitation Evapotranspiration Index (SPEI) at monthly, seasonal, and annual temporal scales to map the spatiotemporal change dynamics of drought characteristics (distribution, frequency, duration, and severity) in Afghanistan. SPEI indices were mapped for river basins, disaggregated into 189 sub-catchments, using monthly precipitation and potential evapotranspiration derived from temperature station observations from 1980 to 2017. The results show these multi-dimensional drought characteristics vary along different years, change among sub-catchments, and differ across temporal scales. During the 38 years, the driest decade and period are the 2000s and 1999–2022, respectively. The 2000–01 water year is the driest, with the whole country experiencing ‘severe’ to ‘extreme’ drought, more than 53% (87 sub-catchments) suffering the worst drought in history, and about 58% (94 sub-catchments) having ‘very frequent’ drought (7 to 8 months) or ‘extremely frequent’ drought (9 to 10 months). The estimated seasonal duration and severity present significant variations across the study area and throughout the study period. The nation also suffered from recurring droughts with varying length and intensity in 2004, 2006, 2008, and, most recently, 2011. There is a trend towards increasing drought with longer duration and higher severity extending all over sub-catchments from southeast to north and central regions. These datasets and maps help to fill the knowledge gap on detailed sub-catchment scale meteorological drought characteristics in Afghanistan. The study findings improve our understanding of the influences of climate change on drought dynamics and can guide catchment planning for reliable adaptation to and mitigation against future droughts.

Keywords: SPEI, precipitation, evapotranspiration, climate extremes

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Authors: Fayiz Saifurahman, Noori Fida Mohammad

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Afghanistan produces the highest rate of wheat, it is the first source of food, and food security in Afghanistan is dependent on the availability of wheat. Although Afghanistan is the main producer of wheat, on the other hand, Afghanistan is the largest importers of flour. The objective of this study is to assess the structure and dynamics of the wheat market in Afghanistan, can compute with foreign markets, and increase the level of production. To complete this, a broad series of secondary data was complied with, group discussions and interviews with farmers, agricultural and market experts. The research findings propose that; the government should adopt different policies to support the local market. The government should distribute the seed, support financially and technically to increase wheat production.

Keywords: Afghanistan, wheat, production , import

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Authors: David Sudre

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Today, the National Basketball Association (NBA) is the cultural model of reference for most of the French basketball community stakeholders (players, coaches, team and league managers). In addition to the strong impact it has on how this sport is played and perceived, the NBA also influences the ways professional basketball shows are organized in France (within the Jeep Elite league). The objective of this research is to see how and to what extent the NBA show, as a globalized cultural product, disrupts Jeep Elite's professional basketball cultural codes in the organization of its shows. The article will aim at questioning the intercultural phenomenon at stake in sports cultures in France through the prism of the basketball match. This angle will shed some light on the underlying relationships between local and global elements. The results of this research come from a one-year survey conducted in a small town in northern France, Le Portel, where the Etoile Sportive Saint Michel (ESSM), a Jeep Elite's club, operates. An ethnographic approach was favored. It entailed many participating observations and semi-directive interviews with supporters of the ESSM Le Portel. Through this ethnographic work with the team's fan groups (before the games, during the games and after the games), it was possible for the researchers to understand better all the cultural and identity issues that play out in the "Cauldron," the basketball arena of the ESSM Le Portel. The results demonstrate, at first glance, that many basketball events organized in France are copied from the American model. It seems difficult not to try to imitate the American reference that the NBA represents, whether it be at the French All-Star Game or a Jeep Elite Game at Le Portel. In this case, an acculturation process seems to occur, not only in the way people play but also in the creation of the show (cheerleaders, animations, etc.). However, this American culture of globalized basketball, although re-appropriated, is also being modified by the members of ESSM Le Portel within their locality. Indeed, they juggle between their culture of origin and their culture of reference to build their basketball show within their sociocultural environment. In this way, Le Portel managers and supporters introduce elements that are characteristic of their local culture into the show, such as carnival customs and celebrations, two ingredients that fully contribute to the creation of their identity. Ultimately, in this context of "glocalization," this research will ascertain, on the one hand, that the identity of French basketball becomes harder to outline, and, on the other hand, that the "Cauldron" turns out to be a place to preserve (fantasized) local identities, or even a place of (unconscious) resistance to the dominant model of American basketball culture.

Keywords: basketball, carnival, culture, globalization, identity, show, sport, supporters.

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Authors: A. Shaygani, R. Saifi, M. S. Saidi, M. Sani

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Particle size distribution, the most important characteristics of aerosols, is obtained through electrical characterization techniques. The dynamics of charged nano-particles under the influence of electric field in electrical mobility spectrometer (EMS) reveals the size distribution of these particles. The accuracy of this measurement is influenced by flow conditions, geometry, electric field and particle charging process, therefore by the transfer function (transfer matrix) of the instrument. In this work, a wire-cylinder corona charger was designed and the combined field-diffusion charging process of injected poly-disperse aerosol particles was numerically simulated as a prerequisite for the study of a multi-channel EMS. The result, a cloud of particles with non-uniform charge distribution, was introduced to the EMS. The flow pattern and electric field in the EMS were simulated using computational fluid dynamics (CFD) to obtain particle trajectories in the device and therefore to calculate the reported signal by each electrometer. According to the output signals (resulted from bombardment of particles and transferring their charges as currents), we proposed a modification to the size of detecting rings (which are connected to electrometers) in order to evaluate particle size distributions more accurately. Based on the capability of the system to transfer information contents about size distribution of the injected particles, we proposed a benchmark for the assessment of optimality of the design. This method applies the concept of Von Neumann entropy and borrows the definition of entropy from information theory (Shannon entropy) to measure optimality. Entropy, according to the Shannon entropy, is the ''average amount of information contained in an event, sample or character extracted from a data stream''. Evaluating the responses (signals) which were obtained via various configurations of detecting rings, the best configuration which gave the best predictions about the size distributions of injected particles, was the modified configuration. It was also the one that had the maximum amount of entropy. A reasonable consistency was also observed between the accuracy of the predictions and the entropy content of each configuration. In this method, entropy is extracted from the transfer matrix of the instrument for each configuration. Ultimately, various clouds of particles were introduced to the simulations and predicted size distributions were compared to the exact size distributions.

Keywords: aerosol nano-particle, CFD, electrical mobility spectrometer, von neumann entropy

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Authors: K. P. Mredula, D. C. Vakaskar

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The article traces developments and evolution of various algorithms developed for solving partial differential equations using the significant combination of wavelet with few already explored solution procedures. The approach depicts a study over a decade of traces and remarks on the modifications in implementing multi-resolution of wavelet, finite difference approach, finite element method and finite volume in dealing with a variety of partial differential equations in the areas like plasma physics, astrophysics, shallow water models, modified Burger equations used in optical fibers, biology, fluid dynamics, chemical kinetics etc.

Keywords: multi-resolution, Haar Wavelet, partial differential equation, numerical methods

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Authors: Lev Chernyshev, Ekaterina Lieshout, Natalia Kabaliuk

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Sit-skis enable individuals with limited lower limb or core movement to ski unassisted confidently. The rise in popularity of the Winter Paralympics has seen an influx of engineering innovation, especially for the Downhill and Super-Giant Slalom events, where the athletes achieve speeds as high as 160km/h. The growth in the sport has inspired recent research into sit-ski aerodynamics. Crosswinds are expected in mountain climates and, therefore, can greatly impact a skier's maneuverability and aerodynamics. This research investigates the impact of crosswinds on the drag force of a Paralympic sit-ski using Computational Fluid Dynamics (CFD). A Paralympic sit-ski with a model of a skier, a leg cover, a bucket seat, and a simplified suspension system was used for CFD analysis in ANSYS Fluent. The hybrid initialisation tool and the SST k–ω turbulence model were used with two tetrahedral mesh bodies of influence. The crosswinds (10, 30, and 50 km/h) acting perpendicular to the sit-ski's direction of travel were simulated, corresponding to the straight-line skiing speeds of 60, 80, and 100km/h. Following the initialisation, 150 iterations for both first and second order steady-state solvers were used, before switching to a transient solver with a computational time of 1.5s and a time step of 0.02s, to allow the solution to converge. CFD results were validated against wind tunnel data. The results suggested that for all crosswind and sit-ski speeds, on average, 64% of the total drag on the ski was due to the athlete's torso. The suspension was associated with the second largest overall sit-ski drag force contribution, averaging at 27%, followed by the leg cover at 10%. While the seat contributed a negligible 0.5% of the total drag force, averaging at 1.2N across the conditions studied. The effect of the crosswind increased the total drag force across all skiing speed studies, with the drag on the athlete's torso and suspension being the most sensitive to the changes in the crosswind magnitude. The effect of the crosswind on the ski drag reduced as the simulated skiing speed increased: for skiing at 60km/h, the drag force on the torso increased by 154% with the increase of the crosswind from 10km/h to 50km/h; whereas, at 100km/h the corresponding drag force increase was halved (75%). The analysis of the flow and pressure field characteristics for a sit-ski in crosswind conditions indicated the flow separation localisation and wake size correlated with the magnitude and directionality of the crosswind relative to straight-line skiing. The findings can inform aerodynamic improvements in sit-ski design and increase skiers' medalling chances.

Keywords: sit-ski, aerodynamics, CFD, crosswind effects

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Authors: Zeleke Ayalew Alemu

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Indian Ocean and the Nile River play significant roles in shaping the hydrological and ecological systems of the regions they traverse. This study explores the interlinkages and impacts of the Indian Ocean on the Nile River, highlighting key factors such as water flow, nutrient distribution, climate patterns, and biodiversity. The Indian Ocean serves as a major source of moisture for the Nile River, contributing to its annual flood cycle and sustaining the river's ecosystem. The Indian Ocean's monsoon winds influence the amount of rainfall received in East Africa, which directly impacts the Nile's water levels. These monsoonal patterns create a vital connection between the Indian Ocean and the Nile, affecting agricultural productivity, freshwater availability, and overall river health. The Indian Ocean also influences the nutrient levels in the Nile River. Coastal upwelling driven by oceanic currents brings nutrient-rich waters from the depths of the ocean to the surface. These nutrients are transported by ocean currents towards the Red Sea and subsequently enter the Nile. This influx of nutrients supports the growth of plankton, which forms the basis of the river's food web and sustains various aquatic species. Additionally, the Indian Ocean's climate patterns, such as El Niño and Indian Ocean Dipole events, exert influence on the Nile River basin. El Niño, for example, can result in drought conditions, reduced precipitation, and altered river flows, impacting agricultural activities and water resource management along the Nile. The Indian Ocean Dipole events can influence the rainfall distribution in East Africa, further impacting the Nile's water levels and ecosystem dynamics. The Indian Ocean's biodiversity is interconnected with the Nile River's ecological system. Many species that inhabit the Indian Ocean, such as migratory birds and marine mammals, migrate along the Nile River basin, utilizing its resources for feeding and breeding purposes. The health of the Indian Ocean's ecosystem thus indirectly affects the biodiversity and ecological balance of the Nile River. Indian Ocean plays a crucial role in shaping the dynamics of the Nile River. Its influence on water flow, nutrient distribution, climate patterns, and biodiversity highlights the complex interdependencies between these two important water bodies. Understanding the interconnectedness and impacts of the Indian Ocean on the Nile is essential for effective water resource management and conservation efforts in the region.

Keywords: water, management, environment, planning

Procedia PDF Downloads 98

Authors: Shashi Kant Verma, S. L. Sinha, D. K. Chandraker

Abstract:

Numerical simulations of selected subchannel tracer (Potassium Nitrate) based experiments have been performed to study the capabilities of state-of-the-art of Computational Fluid Dynamics (CFD) codes. The Computational Fluid Dynamics (CFD) methodology can be useful for investigating the spacer effect on turbulent mixing to predict turbulent flow behavior such as Dimensionless mixing scalar distributions, radial velocity and vortices in the nuclear fuel assembly. A Gibson and Launder (GL) Reynolds stress model (RSM) has been selected as the primary turbulence model to be applied for the simulation case as it has been previously found reasonably accurate to predict flows inside rod bundles. As a comparison, the case is also simulated using a standard k-ε turbulence model that is widely used in industry. Despite being an isotropic turbulence model, it has also been used in the modeling of flow in rod bundles and to produce lateral velocities after thorough mixing of coolant fairly. Both these models have been solved numerically to find out fully developed isothermal turbulent flow in a 30º segment of a 54-rod bundle. Numerical simulation has been carried out for the study of natural mixing of a Tracer (Passive scalar) to characterize the growth of turbulent diffusion in an injected sub-channel and, afterwards on, cross-mixing between adjacent sub-channels. The mixing with water has been numerically studied by means of steady state CFD simulations with the commercial code STAR-CCM+. Flow enters into the computational domain through the mass inflow at the three subchannel faces. Turbulence intensity and hydraulic diameter of 1% and 5.9 mm respectively were used for the inlet. A passive scalar (Potassium nitrate) is injected through the mass fraction of 5.536 PPM at subchannel 2 (Upstream of the mixing section). Flow exited the domain through the pressure outlet boundary (0 Pa), and the reference pressure was 1 atm. Simulation results have been extracted at different locations of the mixing zone and downstream zone. The local mass fraction shows uniform mixing. The effect of the applied turbulence model is nearly negligible just before the outlet plane because the distributions look like almost identical and the flow is fully developed. On the other hand, quantitatively the dimensionless mixing scalar distributions change noticeably, which is visible in the different scale of the colour bars.

Keywords: single-phase flow, turbulent mixing, tracer, sub channel analysis

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Authors: Kerols Seif Said Botros

Abstract:

The relationship between development and human rights has been debated for a long time. Various principles, from the right to development to development-based human rights, are applied to understand the dynamics between these two concepts. Despite the measures calculated, the connection between enhancement and human rights remains vague. Despite, the connection between these two opinions and the need to strengthen human rights have increased in recent years. It will then be examined whether the right to sustainable development is acceptable or not. In various human rights instruments and this is a good vibe to the request cited above. The book then cites domestic and international human rights treaties, as well as jurisprudence and regulations defining human rights institutions, to support this view.

Keywords: sustainable development, human rights, the right to development, the human rights-based approach to development, environmental rights, economic development, social sustainability human rights protection, human rights violations, workers’ rights, justice, security.

Procedia PDF Downloads 54

Authors: Alexandra Andrade Brandão Soares, Paulo Batista Gonçalves

Abstract:

Using a modal expansion that satisfies the boundary and continuity conditions and expresses the modal couplings characteristic of cylindrical shells in the nonlinear regime, the equations of motion are discretized using the Galerkin method. The resulting algebraic equations are solved by the Newton-Raphson method, thus obtaining the nonlinear frequency-amplitude relation. Finally, a parametric analysis is conducted to study the influence of the geometry of the shell, the gradient of the functional material and vibration modes on the degree and type of nonlinearity of the cylindrical shell, which is the main contribution of this research work.

Keywords: cylindrical shells, dynamics, functionally graded material, nonlinear vibrations

Procedia PDF Downloads 65

Authors: Zeinab Yazdanfar, Dilan Robert, Daniel Lester, S. Setunge

Abstract:

Scour has been identified as the most common threat to bridge stability worldwide. Traditionally, scour around bridge piers is calculated using the empirical approaches that have considerable limitations and are difficult to generalize. The multi-physic nature of scouring which involves turbulent flow, soil mechanics and solid-fluid interactions cannot be captured by simple empirical equations developed based on limited laboratory data. These limitations can be overcome by direct numerical modeling of coupled hydro-mechanical scour process that provides a robust prediction of bridge scour and valuable insights into the scour process. Several numerical models have been proposed in the literature for bridge scour estimation including Eulerian flow models and coupled Euler-Lagrange models incorporating an empirical sediment transport description. However, the contact forces between particles and the flow-particle interaction haven’t been taken into consideration. Incorporating collisional and frictional forces between soil particles as well as the effect of flow-driven forces on particles will facilitate accurate modeling of the complex nature of scour. In this study, a coupled Computational Fluid Dynamics and Discrete Element Model (CFD-DEM) has been developed to simulate the scour process that directly models the hydro-mechanical interactions between the sediment particles and the flowing water. This approach obviates the need for an empirical description as the fundamental fluid-particle, and particle-particle interactions are fully resolved. The sediment bed is simulated as a dense pack of particles and the frictional and collisional forces between particles are calculated, whilst the turbulent fluid flow is modeled using a Reynolds Averaged Navier Stocks (RANS) approach. The CFD-DEM model is validated against experimental data in order to assess the reliability of the CFD-DEM model. The modeling results reveal the criticality of particle impact on the assessment of scour depth which, to the authors’ best knowledge, hasn’t been considered in previous studies. The results of this study open new perspectives to the scour depth and time assessment which is the key to manage the failure risk of bridge infrastructures.

Keywords: bridge scour, discrete element method, CFD-DEM model, multi-phase model

Procedia PDF Downloads 131

Authors: Thien X. Dinh, Peter Witt

Abstract:

A one-dimensional model for the simulation of condensation and solidification of a metallurgical vapor in the mixture of gas during supersonic expansion is presented. In the model, condensation is based on critical nucleation and drop-growth theory. When the temperature falls below the supercooling point, all the formed liquid droplets in the condensation phase are assumed to solidify at an infinite rate. The model was verified with a Computational Fluid Dynamics simulation of magnesium vapor condensation and solidification. The obtained results are in reasonable agreement with CFD data. Therefore, the model is a promising, efficient tool for use in the design process for supersonic nozzles applied in mineral processes since it is faster than the CFD counterpart by an order of magnitude.

Keywords: condensation, metallurgical flow, solidification, supersonic expansion

Procedia PDF Downloads 63

Authors: J. T. Manhire

Abstract:

A tax authority wants to take actions it knows will foster the greatest degree of voluntary taxpayer compliance to reduce the “tax gap.” This paper suggests that even if a tax authority could attain a state of complete knowledge, there are constraints on whether and to what extent such actions would result in reducing the macro-level tax gap. These limits are not merely a consequence of finite agency resources. They are inherent in the system itself. To show that this is one possible interpretation of the tax gap data, the paper formulates known results in a different way by analyzing tax compliance as a population with a single covariate. This leads to a standard use of the logistic map to analyze the dynamics of non-compliance growth or decay over a sequence of periods. This formulation gives the same results as the tax gap studies performed over the past fifty years in the U.S. given the published margins of error. Limitations and recommendations for future work are discussed, along with some implications for tax policy.

Keywords: income tax, logistic map, tax compliance, tax law

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Authors: Boguslaw Schreyer

Abstract:

In some types of wheeled robots it is important to secure starting acceleration and deceleration maxima while at the same time maintaining transversal stability. In this paper torque distribution between the front and rear wheels as well as the timing of torque application have been calculated. Both secure an optimum traction coefficient. This paper also identifies required input signals to a control unit, which controls the torque values and timing. Using a three dimensional, two mass model of a robot developed by the author a computer simulation was performed confirming the calculations presented in this paper. These calculations were also implemented and confirmed during military robot testing.

Keywords: robot dynamics, torque distribution, traction coefficient, wheeled robots

Procedia PDF Downloads 312

Authors: Y. Johnson

Abstract:

Study of multi-satellite formation flight systems has drawn wide attention recently due to so many potential advantages. The present work aims to model the relative motion dynamics in terms of change in classical orbital parameters between the two satellites-chief and deputy- under Earth’s oblateness effect. The required impulsive thrust control is calculated to minimize these orbital parameter changes. The formation configuration is initialized by selecting a set of orbital parameters for the chief and deputy satellites such that bounded motion is maintained for a long time in a J_2-invariant relative non-circular orbit between the satellites. The solution of J_2-modified Hill’s equations is also derived in this paper.

Keywords: satellite, formation flight, j2 effect, control

Procedia PDF Downloads 273

Authors: S. Etaig, R. Hasan, N. Perera

Abstract:

This paper analyses the heat transfer performance and fluid flow using different nanofluids in a square enclosure. The energy equation and Navier-Stokes equation are solved numerically using finite volume scheme. The effect of volume fraction concentration on the enhancement of heat transfer has been studied icorporating the Brownian motion; the influence of effective thermal conductivity on the enhancement was also investigated for a range of volume fraction concentration. The velocity profile for different Rayleigh number. Water-Cu, water AL2O3 and water-TiO2 were tested.

Keywords: computational fluid dynamics, natural convection, nanofluid and thermal conductivity

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Authors: Swati Arun

Abstract:

The present paper argues that Balance of Power (BOP) needs to conjugate with certain contingencies like geography. It is evident that sea powers (‘insular’ for better clarity) are not balanced (if at all) in the same way as land powers. Its apparent that artificial insularity that the US has achieved reduces the chances of balancing (constant) and helps it maintain preponderance (variable). But how precise is this approach in assessing the dynamics between China’s rise and reaction of other powers and US. The ‘evolved’ theory can be validated by putting China and US in the equation. Systemic Relation between the nations was explained through the Balance of Power theory much before the systems theory was propounded. The BOP is the crux of functionality of ‘power relation’ dynamics which has played its role in the most astounding ways leading to situations of war and peace. Whimsical; but true that, the BOP has remained a complicated and indefinable concepts since Hans. Morganthau to Kenneth Waltz. A challenge of the BOP, however remains; “ that it has too many meanings”. In the recent times it has become evident that the myriad of expectations generated by BOP has not met the practicality of the current world politics. It is for this reason; the BoP has been replaced by Preponderance Theory (PT) to explain prevailing power situation. PT does provide an empirical reasoning for the success of this theory but fails in a abstract logical reasoning required for making a theory universal. Unipolarity clarifies the current system as one where balance of power has become redundant. It seems to reach beyond the contours of BoP, where a superpower does what it must to remain one. The centrality of this arguments pivots around - an exception, every time BOP fails to operate, preponderance of power emerges. PT does not sit well with the primary logic of a theory because it works on an exception. The evolution of such a pattern and system where BOP fails and preponderance emerges is absent. The puzzle here is- if BOP really has become redundant or it needs polishing. The international power structure changed from multipolar to bipolar to unipolar. BOP was looked at to provide inevitable logic behind such changes and answer the dilemma we see today- why US is unchecked, unbalanced? But why was Britain unchecked in 19th century and why China was unbalanced in 13th century? It is the insularity of the state that makes BOP reproduce “imbalance of power”, going a level up from off-shore balancer. This luxury of a state to maintain imbalance in the region of competition or threat is the causal relation between BOP’s and geography. America has applied imbalancing- meaning disequilibrium (in its favor) to maintain the regional balance so that over time the weaker does not get stronger and pose a competition. It could do that due to the significant parity present between the US and the rest.

Keywords: balance of power, china, preponderance of power, US

Procedia PDF Downloads 278